Improved roofing



J. DUKE. RooPING.

No. 34,200. Patented Jan. 21, 1862.

' UNITED "STATES,

PATENT OFFICE.

JOI'IN DUKE, OF MILEYSBURG, PENNSYLVANIA.

IM PROVED ROOFBNG.

Specification forming part of Letters Patent No. 34,20),-dated January21,1862.

To all whom it may concern.-

Beit known that I; JOHN DUKE, of vMilesburg, in the county of Center, inthe State of Pennsylvania, have invented a new and Im proved Mode ofRoofing; and I do hereby declare that the following is a full and exactdecrption thereof.

The composition which I use for the formation of the roof is composed ofthe following ingredients,viz: gas-tar or coaltar, fine gravel 'andsand, and plaster. These ingredients are compounded in the followingmanner, varying some little in their proportions, according to thenature and purity. of the sand used: Mix the gravel, sand, and plas-`ter, taking two parts of such gravel-and sand as can be sifted through aquarter or half inch riddle and one part -plaster. Combine with thismixture a sufficient quantity of gastar orcoal-tar to thoroughlyaturatcthe mixture. 'lhe composition is then ready to use.

I form the base of the roof on which the composition is to be placed bycovering the rafters with boards of dierent thickness, succeeding eachother alternately, as represented in Figure 2of the accompanyingdrawings by the small letters a and b.

I spread the compound from one-half to' JOHN DUKE.

Witnesses.:

C.' G.. RYMAN, B. B. ELSE.

